A small explosion during a training demonstration for Massachusetts State Police personnel and hazmat crews last June resulted in several people being checked for injuries, according to officials. 

A newly released video shows the moments leading up to the June 20 blast, which occurred during a four-day training on illegal drug laboratory safety concerns, according to Jake Wark, a spokesman for the state Department of Fire Services. A State Police vendor was leading a demonstration that involved mixing two commonly available chemicals found in illicit labs, and the substances reacted in a plastic soda bottle, Wark explained. 

“Even when handled by trained professionals under controlled conditions, the chemicals used in illicit drug manufacturing are unpredictable and pose a risk of fire, explosion, and injury,” he said in a statement. “This is exactly the reason we train and prepare for them.” 

According to Wark, the two State Police personnel involved in the demonstration were wearing appropriate personal protective gear at all times, and crews used water from a nearby fire engine to mitigate any hazards.

“They and several others were assessed for injuries at the scene but none required transport,” Wark said. There were no reported injuries from staff at DFS, which hosted the training, he added. 

News of the explosion first spread via WBZ, which reported that more than a dozen State Police members were checked for injuries following the incident. State Police did not immediately respond to a request for comment Thursday on medical evaluations or injuries among personnel who participated in the demonstration.

Wark said the vendor, whom he did not identify, is replacing $35,746 of personal protective equipment and other gear taken out of service following the explosion.